This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for A Study of Mircera (C.E.R.A.) in Patients With Pre-Dialysis Chronic Renal Anemia (NCT01342640), a na phase 4 study. The primary outcome is Change From Baseline in Mean Hb Concentration at Week 20.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01342640 |
| Phase | Phase 4 |
| Condition | Anemia |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 70 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Hoffmann-La Roche |
| Results posted | Yes |
2. Clinical Question
Population
Patients with chronic renal anemia who were not on dialysis and were not currently treated with an ESA, as described in the official title. The registry record does not report further eligibility details.
Intervention
Methoxy polyethylene glycol-epoetin beta, identified as Mircera or C.E.R.A. The recommended starting dose was 1.2 micrograms subcutaneously every 4 weeks, dependent on weight, with possible dose adjustment for inadequate or excessive response.
Comparator
There was no comparator arm. This was a single-arm, open-label study, so the record does not describe a randomized or concurrent control group.
Primary question
What was the change from baseline in mean hemoglobin concentration at Week 20 among participants in the per-protocol population? The primary outcome is named, but its numerical estimate and variability are not reported in the registry record.
The clinical question is therefore descriptive: it concerns hemoglobin change and safety during treatment in the enrolled study population. Without a control group, the trial cannot directly estimate how the observed course compares with no treatment or with another intervention. The open-label design also means that participants and study personnel were not masked to treatment assignment; there was no assignment to a different treatment in this single-group study.
The primary endpoint description defines the per-protocol population using treatment-period observations, withdrawal, dosing, and iron-status criteria. These restrictions matter when interpreting whom the endpoint represents. The registry record does not report the numerical endpoint result, the number analyzed for that endpoint, or the baseline and Week 20 mean values. Consequently, the direction and size of the reported hemoglobin change cannot be established from the record.
3. Trial Design
This was a completed Phase 4, single-arm, open-label, multicenter clinical trial sponsored by Hoffmann-La Roche. The registry record gives an enrollment of 70. The study began on 2011-07-18, and primary completion was recorded as 2012-11-30. Allocation is listed as not applicable, consistent with the single-group model; masking is listed as none.
Participants received methoxy polyethylene glycol-epoetin beta, named Mircera or C.E.R.A. In the record. The brief summary describes a recommended starting dose of 1.2 micrograms by subcutaneous administration every 4 weeks. The dose depended on participant weight, and adjustment could be required in response to inadequate or excessive treatment response. Anticipated time on study treatment was 28 weeks. The registry record does not report individual treatment durations or actual dose changes.
The primary endpoint was change from baseline in mean hemoglobin concentration at Week 20, measured in grams per deciliter. The endpoint description refers to the per-protocol population and to an efficacy evaluation period spanning Weeks 20 to 28. It specifies exclusions based on the number of recorded hemoglobin values, missed treatment doses, withdrawal before the efficacy evaluation period, and inadequate iron status. Further details about how those criteria were applied to individual participants are not reported in the registry record.
The design supports a description of outcomes observed during treatment in this group. It does not provide a randomized comparison with another treatment or a control group. The record does not report additional design details such as the recruitment setting, eligibility criteria beyond the stated population, or how the multicenter sites were selected. Enrollment does not establish how many participants contributed data to each analysis; the endpoint-specific analyzed count is not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Methoxy Polyethylene Glycol-Epoetin Beta |
|---|---|
| STARTED | 70 |
| COMPLETED | 29 |
| NOT COMPLETED | 41 |
Reasons for not completing this period:
| Reason | Methoxy Polyethylene Glycol-Epoetin Beta |
|---|---|
| Adverse Event | 3 |
| Protocol Violation | 16 |
| Lost to Follow-up | 21 |
| Other | 1 |
Analysis population for the primary outcome, as defined in the registry: PP Population. Here, number of participants analyzed (N) signifies those participants who were evaluable for this outcome and n signifies those participants who were evaluable for specified time-point.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
Population: Intent-to-Treat (ITT) Population: All participants who received at least 1 dose of methoxy polyethylene glycol-epoetin beta treatment and for whom at least 1 follow-up data was available.
| Characteristic | Unit | Methoxy Polyethylene Glycol-Epoetin Beta |
|---|---|---|
| Participants analysed | 70 | |
| Age, Continuous | Years | 45.80 (SD 16.68) |
| Sex: Female, Male: Female | Participants | 45 |
| Sex: Female, Male: Male | Participants | 25 |
6. Primary Endpoint
The registry lists the primary outcome as Change From Baseline in Mean Hb Concentration at Week 20, measured over Baseline (Week 0), Week 20.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Standard Deviation |
| Unit | Grams per deciliter (gm/dL) |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is change from baseline in mean hemoglobin concentration at Week 20, expressed in grams per deciliter. Hemoglobin is the measured quantity named by the trial as its primary efficacy outcome. The endpoint focuses on change rather than only the Week 20 measurement, allowing a participant’s later measurement to be interpreted relative to the baseline measurement. In general, change-from-baseline outcomes can help describe within-participant movement over the study period, but a single-arm design does not separate treatment-associated change from other influences over time.
The registry record says the endpoint used the per-protocol population. Participants were excluded from that population if they had fewer than 3 recorded hemoglobin values in Weeks 20 to 28, missed a dose in Weeks 20 to 28, withdrew before the efficacy evaluation period, or had inadequate iron status during that period. Inadequate iron status was defined using mean serum ferritin at or below 100 nanograms per milliliter, mean transferrin saturation at or below 20%, or mean hypochromic red blood cells at or above 10%.
The record names the summary measure as a mean and identifies standard deviation as the dispersion measure. However, it does not report the endpoint estimate, standard deviation, or analyzed participant count. The size and precision of the Week 20 change therefore cannot be described from the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a primary endpoint, but does not report its numerical result. It gives no mean change from baseline, standard deviation, confidence interval, p-value, or endpoint-specific analyzed count. As a result, the magnitude, direction, and statistical precision of the primary outcome are not reported in the registry record. No conclusion about the observed hemoglobin change can be drawn from the endpoint title alone.
The study’s single-arm design is central to interpretation. Any outcome measured during treatment describes what occurred in the enrolled group over the study period. Without a concurrent comparator, the design cannot show how those outcomes would have differed under another treatment or without the study intervention. Changes over time can also reflect influences other than treatment. This is a general limitation of uncontrolled before-and-after comparisons, not a reported finding about this particular study.
The per-protocol definition further narrows the endpoint population. It excludes participants for specified treatment-period data, dosing, withdrawal, and iron-status reasons. That population is not automatically interchangeable with all enrolled participants or with the safety population, which the record defines as all enrolled participants. The number excluded for each reason and the final per-protocol count are not reported in the registry record. Without these details, the extent to which the analyzed group differs from all enrolled participants cannot be assessed.
The record reports adverse-event figures for the treatment group: 7 of 70 participants are listed in the serious adverse event category, and 7 of 70 in the other adverse event category. Six serious adverse event terms are listed, each with a reported frequency of 1.4%. These entries describe reported events in this study group; in the absence of a comparator, they do not quantify differences in risk between treatments. The registry record does not report deaths in the adverse-event entry.
The trial is recorded as completed, but completion does not supply missing outcome estimates or establish the completeness of endpoint data. The record does not report a numerical efficacy result, confidence interval, or analysis details beyond the stated endpoint and population definition. Accordingly, interpretation should remain limited to the design and outcome information that the registry record actually reports.
9. Statistical Methods Explained
Statistical methods describe how observations are summarized and how uncertainty is assessed. The registry record identifies the primary outcome as a continuous measure: mean change in hemoglobin concentration from baseline to Week 20. It names standard deviation as the dispersion measure. The record does not provide the numerical mean change, standard deviation, confidence interval, or p-value, and does not report enough information to reproduce an analysis of the primary endpoint.
What does a mean change represent?
In general, a mean change is calculated by finding the change for each participant with the required measurements and then summarizing those individual changes. It describes the average change in the analyzed group, rather than the change for every participant. A mean can be influenced by unusually large or small individual changes. A standard deviation describes how spread out the individual values are around the mean; it is not the same as the uncertainty in the estimated mean.
The endpoint title refers to change from baseline in mean hemoglobin at Week 20, while the population description refers to recorded values during Weeks 20 to 28. This may reflect the endpoint’s specified evaluation rules, but the registry record does not explain the detailed calculation used to produce a participant’s endpoint value across that period. The exact handling of repeated measurements and missing visits is not reported.
How should uncertainty be understood?
In general, a confidence interval gives a range of values compatible with the observed data and the statistical model used. Its width reflects precision: wider intervals indicate less precision, while narrower intervals indicate greater precision, under the assumptions of the method. A confidence interval is not reported for this endpoint in the registry record. There is therefore no reported interval with which to assess precision.
A p-value, when reported, measures how unusual the data would be under a specified null hypothesis and model. It does not measure the size or clinical importance of an effect. The registry record does not report a p-value or a null hypothesis for the primary endpoint. Statistical significance therefore cannot be assessed from the record, and it would not substitute for an estimate of the change and its uncertainty.
What does the single-group design allow?
In general, a single-arm study can describe outcomes among participants receiving the study intervention. It does not provide a randomized control group against which to estimate a treatment contrast. A baseline measurement is not a substitute for a concurrent control: it is taken at another time, and other changes during follow-up can affect the outcome. This means a within-group change, even if reported, would not by itself isolate the effect attributable to treatment.
The trial is open label and has no masking. In general, lack of masking can affect participant behavior, clinical decisions, reporting, and outcome assessment, depending on the outcome and its measurement. Hemoglobin is a laboratory measure, but the registry record does not describe laboratory procedures, central review, or whether outcome assessors were otherwise kept unaware of treatment information. These details are not reported in the registry record.
What does the analysis population mean?
The primary outcome uses a per-protocol population defined by specified criteria. The registry record describes this population as drawn from the safety population, meaning all enrolled participants, with exclusions for insufficient recorded hemoglobin values, missed treatment doses during Weeks 20 to 28, withdrawal before the efficacy evaluation period, or inadequate iron status during that period. Such criteria can make the analysis depend on follow-up and treatment adherence. In general, excluding participants after enrollment can affect how representative the analyzed group is of all enrolled participants. The record does not report the count retained or excluded for each criterion.
The registry record does not describe the statistical test or estimation procedure, assumptions used for the primary endpoint, adjustment for baseline factors, or sensitivity analyses. These methods cannot be inferred from the endpoint name or from the designation of standard deviation as the dispersion measure.
What are planning calculations?
In general, sample-size planning illustrations estimate how many participants might be needed under specified assumptions about an effect, variability, allocation, and statistical error rates. Those calculations are planning exercises, not observed trial outcomes and not a measure of the probability that a completed study found an effect. The record’s stated planning assumptions describe a hypothetical two-arm calculation, although the clinical trial itself was single-arm. The observed effect and numerical planning outputs are not reported in the registry record, so those calculations cannot be evaluated from the record. No observed-power claim is supported.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists three outcome measures and three analyses. It does not report a multiplicity plan, including whether any outcomes were designated as secondary or exploratory for formal testing, whether tests were ordered hierarchically, or whether significance thresholds were adjusted. When multiple outcomes or analyses are examined, general statistical practice recognizes that the chance of at least one apparently unusual result can increase if no adjustment or prespecified testing strategy is used. Whether that issue affected interpretation in this study cannot be determined from the registry record.
The primary outcome description specifies a per-protocol population and eligibility rules based on observations, dosing, withdrawal, and iron status. It does not report how missing hemoglobin measurements were handled, whether any values were imputed, or whether participants with incomplete measurements contributed to another analysis. The number of participants missing endpoint data and the reasons for missingness are not reported in the registry record. In general, missing data can affect an estimate when the availability of measurements is related to the outcomes or participant characteristics; the direction and extent of any effect depend on details that are not reported.
The registry record identifies the safety population as all enrolled participants and describes the primary endpoint population as a subset meeting per-protocol criteria. It does not report the analysis population counts for the listed outcomes or explain whether any additional analysis populations were used. It also does not report sensitivity analyses comparing different missing-data assumptions or analysis populations. The endpoint’s numerical estimate and precision are not reported, so the impact of population selection and missing data cannot be assessed.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Methoxy Polyethylene Glycol-Epoetin Beta | 7 | 70 | 10.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Methoxy Polyethylene Glycol-Epoetin Beta | 7 of 70 |
Most frequent serious adverse event terms
| Event term | Organ system | Methoxy Polyethylene Glycol-Epoetin Beta |
|---|---|---|
| Renal failure chronic | Renal and urinary disorders | 1 of 70 |
| Peripheral ischemia | Vascular disorders | 1 of 70 |
| Renal failure | Renal and urinary disorders | 1 of 70 |
| Pneumonia cytomegaloviral | Infections and infestations | 1 of 70 |
| Hemoglobin decreased | Investigations | 1 of 70 |
| Complications of transplanted kidney | Injury, poisoning and procedural complications | 1 of 70 |
| Hypocalcemia | Metabolism and nutrition disorders | 1 of 70 |
| Respiratory failure | Respiratory, thoracic and mediastinal disorders | 1 of 70 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Methoxy Polyethylene Glycol-Epoetin Beta |
|---|---|---|
| Urinary tract infection | Infections and infestations | 7 of 70 |
Serious events with the highest arm-level rate: renal failure chronic (1.4%), peripheral ischemia (1.4%), renal failure (1.4%), pneumonia cytomegaloviral (1.4%), hemoglobin decreased (1.4%).
The registry record lists 70 participants at risk in the methoxy polyethylene glycol-epoetin beta group. It reports 7 participants affected in the serious adverse event category and 7 in the other adverse event category. The record separately lists six serious adverse event terms: renal failure chronic, peripheral ischemia, renal failure, pneumonia cytomegaloviral, hemoglobin decreased, and complications of transplanted kidney. Each term is reported at 1.4%.
These figures should be read as reported safety observations within this study group. The term frequencies do not establish that the events were caused by treatment, and a single-arm study cannot compare their frequency with that under another treatment. The registry record does not report further details such as event timing, duration, outcome, or the number of participants with multiple events. Deaths are not reported in the registry record.
In general, adverse-event summaries depend on how events were collected, coded, and categorized. The record does not describe those procedures in detail. The figures therefore provide a limited account of reported events rather than a complete comparative assessment of safety.
12. What the Result Does, and Does Not, Mean
This study provides a registry record of a completed, open-label, single-arm Phase 4 trial in patients with chronic renal anemia who were not on dialysis. Its named primary outcome is change from baseline in mean hemoglobin concentration at Week 20, with a per-protocol analysis population defined by treatment-period measurements, dosing, withdrawal, and iron-status criteria. The record also contains safety-event counts and listed serious event terms.
The primary outcome’s numerical estimate is not reported in the registry record. Neither its standard deviation nor a confidence interval, p-value, or endpoint-specific analyzed count is reported. Thus, the record does not establish the size, direction, or precision of the Week 20 change. The endpoint’s existence should not be mistaken for a reported result.
Even if an outcome estimate were available, the single-arm design would describe change in the treated group rather than a randomized treatment contrast. A baseline comparison cannot show what would have happened over the same period in a separate control group. The open-label design and per-protocol exclusions are also relevant when considering how outcomes were observed and which participants contributed to the primary analysis.
The adverse-event entries describe events recorded among participants in the treatment group. Without a comparator, they cannot establish relative risk, and the record does not report enough detail to determine causation or fully characterize the events. The listed frequencies should not be interpreted as proof that the intervention did or did not cause a particular event.
Overall, the registry record establishes the study’s design, treatment description, endpoint definition, analysis-population criteria, and limited safety counts. It does not report the numerical primary efficacy outcome or the methods needed to assess its precision. The record therefore supports a description of what the study set out to measure and how its endpoint population was defined, but not a numerical conclusion about the endpoint.
13. Why This Trial Matters Statistically
This trial is statistically notable because its primary outcome is a change measured within a single group, while no concurrent comparator is included. That design can describe the course of a measured outcome over time in participants receiving the intervention. It cannot by itself separate treatment-associated change from other influences that may occur during follow-up. The distinction between a within-group description and a comparative treatment effect is fundamental when interpreting clinical studies.
The population definition is also important. The primary endpoint uses a per-protocol subset with criteria involving the amount of hemoglobin data, treatment dosing, withdrawal, and iron status. The safety population, by contrast, is defined as all enrolled participants. These populations answer different descriptive questions, and the analyzed count for the primary endpoint is not reported in the registry record. Without that count and details of exclusions, readers cannot assess how much the efficacy analysis represents the full enrolled group.
The endpoint is clearly named, and its measure and dispersion type are specified, but the numerical result is absent. This illustrates why an endpoint definition alone is not enough for statistical interpretation. An estimate, a measure of uncertainty, and sufficient analysis details are needed to assess magnitude and precision. Those numerical efficacy details are not reported in the registry record.
The record also lists safety observations, but a single-arm study offers no internal treatment comparison for those events. This limits what the event counts can say about relative safety. The study remains useful as a record of a defined intervention, study population, follow-up plan, and specified outcome; its design and reporting limits must shape any interpretation of what those observations mean.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal trial-specific limitation is the absence of a comparator group. Since the study was single-arm and open label, it cannot provide a randomized contrast or distinguish changes over time from changes attributable to treatment. The registry record does not describe masking or blinded outcome assessment beyond listing masking as none.
The numerical primary outcome is not reported in the registry record. The record also does not report the Week 20 mean change, standard deviation, confidence interval, p-value, or number analyzed. This prevents assessment of the size and precision of the primary endpoint. Although the outcome is identified as a mean continuous measure and standard deviation is named as its dispersion, those labels do not replace the missing estimates.
The endpoint population has detailed exclusions for insufficient hemoglobin measurements, missed doses, withdrawal before the efficacy evaluation period, and inadequate iron status. The registry record does not report how many participants were excluded for each reason or the final per-protocol population count. The handling of missing observations, the calculation of the endpoint across Weeks 20 to 28, and any sensitivity analyses are not reported.
The registry record lists three outcome measures and three analyses but does not report a multiplicity strategy or the statistical procedures used. It also does not report detailed eligibility criteria, actual treatment duration, individual dose changes, or the procedures used to collect and classify adverse events. The safety figures have no concurrent comparison, and further event-level details are not reported. These limitations constrain both efficacy and safety interpretation.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: A Study of Mircera (C.E.R.A.) in Patients With Pre-Dialysis Chronic Renal Anemia — NCT01342640.
- Registry record last updated 2017-07-12; status last verified 2017-06.
- Results first posted 2015-10-26.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry record describes a completed, multicenter, open-label, single-arm Phase 4 study sponsored by Hoffmann-La Roche. Enrollment was 70. The study began on 2011-07-18, with primary completion on 2012-11-30. Participants had chronic renal anemia and were not on dialysis; the official title describes participants as not currently treated with an ESA.
The intervention was methoxy polyethylene glycol-epoetin beta, identified as Mircera or C.E.R.A. The recommended starting dose was 1.2 micrograms subcutaneously every 4 weeks, dependent on weight, with possible dose adjustment. Anticipated treatment time was 28 weeks.
The primary endpoint was change from baseline in mean hemoglobin concentration at Week 20. The per-protocol population had specified data, dosing, withdrawal, and iron-status criteria. The registry record does not report the numerical primary outcome or its precision. It lists 7 participants with serious adverse events and 7 with other adverse events among 70 at risk, with six serious-event terms reported at 1.4% each.